Eş Zamanlı Veri Transferi ile Lcr-Metre ve Doğru Akım Kaynaklarının Senkron Çalıştırılması Sağlanarak Yarıiletken Cihazların Karakterizasyonunda Yeni Yöntem Geliştirilmesi

Organik elektronik alanında üretilen yarıiletken aygıtlar yüksek elektrik alanlar altında tetiklenmektedir ve bu tür aygıtların dielektrik analizini 100-200 V'luk gerilim altında yapan cihazlar piyasada bulunmamaktadır. Bu problemi çözebilmek için yüksek gerilim altında dielektrik analiz yapabilen niteliklere sahip bir ölçüm sistemi geliştirilmiştir. Bunun için geniş bir frekans aralığında birkaç voltluk AC uygulayarak dielektrik spektroskopi analizi yapan cihaza, harici bir DC gerilim kaynağı uygun bir şekilde bağlandı. Bu iki cihazın eşzamanlı çalışması gerekmektedir fakat bu işlemin bağımsız iki cihaz için manuel olarak yapılması oldukça zordur. Bu çalışmada, geliştirdiğimiz eş zamanlı veri transfer programı kullanılarak DC gerilim kaynağı (yarıiletken malzemeler veya aygıtların Akım-Gerilim (I-V) özelliklerinin belirlenmesinde kullanılan) ve LCR Metre cihazının (Kapasitans-Gerilim (C-V), Kapasitans-Frekans (C-f), Kondüktans-Gerilim (G-V) ve Kondüktans-frekans (G-f) özelliklerinin belirlenmesinde kullanılan) eş zamanlı haberleşebilmesi için program geliştirilmiştir. Eş zamanlı veri transfer program ile elde edilen tüm veriler program arayüzünde oluşturulan Excel dosyasına aktarılarak dielektrik spektroskopik özelliklerine ait bilgiler kayıt edilmektedir. Geliştirilen programın literatürde dielektrik özellikleri daha önceden belirlenmiş malzemeler üzerine yapılan ön çalışmalarda tutarlı ve hassas veriler elde edilebildiği ve yüksek bir performansla çalıştığı gözlenmiştir

Applications of Wine Pomace in the Food Industry: Approaches and Functions

Winemaking generates large amounts ofwine pomace, also called grape pomace. This by-product has attracted the attention of food scientists and the food industry, due to its high content in nutrients and bioactive compounds. This review mainly focuses on the different published approaches to the use of wine pomace and its functions in the food industry. Traditionally, wine pomace has been used to obtain wine alcohol, food colorings, and grape seed oil. More recently, research has focused in the production of other value-added products, such as extracts of bioactive compounds, mainly phenols, recovery of tartaric acid, and the making of flours. The most common functions associated with wine pomace products are their use as antioxidants, followed by their use as fortifying, coloring, and antimicrobial agents. These products have mainly been applied to the preparation of meat and fish products and to, a lesser extent, cereal products.Autonomous Government of Castilla y León, Spain, through the research project BU282U13

Prepering schottky barrier diodes (SBDS) with organic interface and investigating their elektrical and dielectric properties in a wide frequency range

YÖK Tez No: 394472Au/PPy/n-Si Schottky bariyer diyotlar (SBD) organik buharlaştırma tekniği sayesinde n-Si üzerine Polyprrole (PPy) organic katmanı oluşturarak üretildi. Yapının dielektrik sabiti (?'), dielektrik kaybı (?''), kayıp tanjantı (tan?), elektrik modülüsün gerçek ve sanal kısımları (M' and M'') ve ac elektriksel iletkenlik parametreleri (?ac)'nin frekansa bağlılığı 10kHz-500kHz frekans aralığında incelendi. Artan frekansla birlikte; ?ac, M' ve M'' değerlerinde artış gözlenirken, ?', ?'' ve tan? değerlerinde azalma görülür. Bunun yanısıra, tan? ve M'' yaklaşık sıfır ön geriliminde artan frekansla azalan bir peak gösterir. Artan gerilimle birlikte; ?'', tan?, ?ac ve M'' değerlerinde olurken gelirken, ?' ve M' değerlerinde azalma olur. ?', ?'', tan?, M', M'' ve ?ac değerlerindeki bu değişiklik yüzey yükü polarizasyonuna ve özellikle de PPy/n-Si arayüzeyine yerleşmiş yüzey durumları yoğunluk dağılımına atfedilir.Au/PPy/n-Si Schottky barrier diodes SBDs were fabricated by forming polypyrrole (PPy) organic layer on n-Si using the organic evaporating technique. Frequency dependent dielectric constant (?'), dielectric loss (?''), loss tangent (tan?), real and imaginary parts of electrical modulus (M' and M'') and AC electrical conductivity (?ac) parameters of the structure were investigated in the frequency range of 10kHz-500kHz. It was found that the values of the ?', ?'' and tan?, in general, decrease with increasing frequency while an increase is observed in ?ac, M' and M''. The tan? and M'' also exhibit a peak at about zero-bias voltage while peak intensity weakens with increasing frequency. The values of ?' and M' decrease with increasing voltage while an increase is observed in ?'', tan?, ?ac and M''. These changes in ?', ?'', tan?, M', M'' and ?ac values was attributed to surface charge polarization and the particular density distribution of surface states localized at PPy/n-Si interface

The preparation of metal-polymer-semiconductor (MPS) and investigation of their electrical and dielectric properties based on frequency and temperature

YÖK Tez No: 536791Bu tez çalışmasında, CdS-PVA arayüzey tabakalı Al/p-Si Metal-Polimer-Yarıiletken (MPY) yapıların elektrik ve dielektrik parametreleri kapasitans-voltaj (C-V), kondüktans-voltaj (G/?-V) ve akım-voltaj (I-V) ölçümlerinden yararlanılarak incelenmiştir. CdS-PVA nanoparçacıkları bilyalı öğütme metodu kullanılarak oluşturuldu ve p-Si üzerine sol-jel metodu ile kaplanmıştır. Omik ve doğrultucu kontaklar termal buharlaştırma yöntemiyle oluşturularak Al/(CdS-PVA)/p-Si yapılarının üretim süreci tamamlanmıştır. Al/(CdS-PVA)/p-Si yapıların yapısal özellikleri; Ultraviyole ve görünür ışık (UV-VIS), X-Ray Powder Diffraction (XRD) ve Scanning Elektron Mikroskobu (SEM) ile incelenirken, kompleks dielektrik (?', ?''), kayıp tanjant (tan?), ac elektriksel iletkenlik (?ac), kompleks elektriksel modülüs (M', M'') gibi dielektrik özellikleri 5 kHz-5 MHz frekans, ±1.0 V voltaj ve 500 kHz'de 230-340 K sıcaklık aralığında analiz edilmiştir. Yüksek frekanslarda ve düşük sıcaklıklarda ?', ?'', tan? ve ?ac değerleri neredeyse sabitken, düşük frekanslar ve yüksek sıcaklıklarda ?', ?'', tan? ve ?ac değerleri ac sinyalini kolayca takip edebilen Nss ve arayüzey polarizasyonlarından dolayı artış göstermektedir. M' ve M'' değerlerinin artan frekans ile birlikte artarken, sıcaklığın artışı ile azaldığı görülmektedir. Bu durum, dc gerilim, frekans ve sıcaklığın etkisi ile arayüzey yüklerin yeniden yapılanıp-düzenlenmesine atfedilmiştir. Al/(CdS-PVA)/p-Si yapıların relaksasyon mekanizmasını belirlemek için M' ve M'' parametrelerinin Argand diyagramları sıcaklığın fonksiyonu olarak incelenmiştir. Arayüzey durumlarının yoğunluğu (Nss)'nin voltaj ve frekansa bağlı özellikleri düşük-yüksek frekanslı kapasitans (CLF-CHF) ve Hill-Coleman yöntemleri ile incelenirken, Rs değerleri Nicollian ve Brews yöntemleri ile elde edilmiştir. Nss ve Rs değerleri artan frekans ile azalmıştır ve Rs etkisini ortadan kaldırmak için düzeltilmiş kapasitans (Cc) ve düzeltilmiş iletkenlik (Gc/?) grafikleri oluşturulmuştur.In this thesis study, electrical and dielectric parameters of Al/p-Si Metal-Polymer-Semiconductor (MPS) type structures with CdS-PVA interfacial layer were investigated using the capacitance (C-V), conductance-voltage (G/?) and current voltage (I-V) measurement data. CdS-PVA nanoparticles were produced using ball milling method and were coated on p-Si by sol-gel method. The process of production of Al/(CdS-PVA)/p-Si type structures were completed by forming omic and rectifier contacts via thermal evaporation method. Al/(CdS-PVA)/p-Si type structures' structural properties were examined with UV-VİS, X-Ray Powder Diffraction (XRD) and Scanning Electron Microscope (SEM). Dielectric properties such as complex dielectric (?', ?''), loss tangent (tan?), ac electrical conductivity (?ac), complex electrical modulus (M', M'') were analyzed in temperature range of 230-340 K at 500 kHz, frequency range of 5 kHz-5 MHz, voltage range of ±1.0 V range. The values of ?', ?'', tan? and of ?ac are almost stable at high frequencies and low temperatures whereas, at low frequencies and high temperatures, the values of ?', ?'', tan? and ?ac show an increase because of interfacial polarizations and surface state (Nss) that follows ac signal easily. M' and M'' values increase with the increasing frequency and are observed to decrease with the increasing temperature. This situation was attributed to restructuring and reordering of the interfacial charges by the effect of dc voltage, frequency and temperature. For the purpose of determining relaxation mechanisms of Al/(CdS-PVA)/p-Si type structures the Argand diagram that was obtained from M' and M'' graphics was analyzed as a function of temperature. The voltage and frequency dependent profiles of density of Nss were investigated with high-low frequency capacitance (CLF-CHF) and Hill-Coleman methods whereas Rs values were obtained using Nicollian and Brews method. It was observed that Nss and Rs values decreased with the increasing frequency. Moreover, corrected capacitance (Cc) and corrected conductance (Gc/?) graphics were drawn to eliminate the effect of Rs

Characterization of Surface States and Their Relaxation Time in Al/ZnO/p-GaAs Structure by Admittance Method at Room Temperature

WOS: 000462778400009Surface state (N-ss) density and their relaxation time (tau) of the fabricated Al/ZnO/p-GaAs structure was investigated in frequency range of 1 kHz-1 MHz and in voltage range of +/- 1.2 V. It was found that the variance of capacitance (C) and conductance (G/omega) with frequency and voltage is basically different especially at low and intermediate frequencies in depletion and accumulation regions. Characteristics of Al/ZnO/p-GaAs structure are affected by parameters such as N-ss, dipole and surface polarization in depletion region at low frequencies, while they are affected by parameters such as interfacial ZnO layer and series resistance (R-s) in accumulation region at higher frequencies. C and G have higher values in low frequency region due to effects such as N-ss in metal-semiconductor interface, interfacial ZnO layer and surface dipole polarization. The rise in C and G has been showed up thanks to the ac signal that can be easily monitored N-ss, strong interface and dipole polarizations, interfacial layer especially at weak inversion and depletion regions. Due to special distribution of N-ss at ZnO/p-GaAs interface, parallel conductance (G(p/omega)) - ln(f) plots show a peak under distinct voltage. Thus, the values of N-ss and omega were determined from the peak values of these plots and changed from 3.92 X 10(12) eV(-1) . cm(2) to 4.33 X 10(12) eV(1) . cm(2) and 6.3 X 10(5) s to 6.3X 10(6) s for 0.35 V and 1.1 V, respectively. These values of N-ss and 1.30 nm RMS roughness (from Atomic Force Microscopy (AFM) image) are very suitable for an electronic device.Duzce University Scientific Research ProjectsDuzce University [2017.07.02.567, 2013.07.02.204]This study was financially supported by Duzce University Scientific Research Projects (Project Numbers: 2017.07.02.567 and 2013.07.02.204)

Dielectric properties and electric modulus of Au/PPy/n-Si (MPS) type Schottky barrier diodes (SBDS) as a function of frequency and applied bias voltage

WOS: 000354761800001Au/PPy/n-Si Schottky barrier diodes (SBDs) were fabricated by forming polypyrrole (PPy) organic layer on n-Si using the spin coating technique. Frequency-dependent dielectric constant (epsilon'), dielectric loss (epsilon ''), loss tangent (tan delta), real and imaginary parts of electrical modulus (M' and M '') and AC electrical conductivity (sigma(ac)) parameters of the structure were investigated in the frequency range of 10-500 kHz. It was found that the values of the epsilon', epsilon '' and tan delta, in general, decrease with increasing frequency while an increase is observed in sigma(ac), M' and M ''. The tan delta and M '' also exhibit a peak at about zero-bias voltage, while peak intensity weakens with increasing frequency. The values of epsilon' and M' decrease with increasing voltage while an increase is observed in epsilon '', tan delta sigma(ac) and M ''. These changes in epsilon', epsilon '', tan delta, M', M '' and sigma(ac) values was attributed to surface charge polarization and the particular density distribution of surface states localized at PPy/n-Si interface.Duzce University BAP research ProjectDuzce University [2013.07.02.204]; Nigde University BAP research ProjectOmer Halis Demir University [2012/022]This work is supported by Duzce University BAP research Project No. 2013.07.02.204 and Nigde University BAP research Project No. 2012/022

On the Frequency-Voltage Dependence Profile of Complex Dielectric, Complex Electric Modulus and Electrical Conductivity in Al/ZnO/p-GaAs Type Structure at Room Temperature

WOS: 000480420100013The real and imaginary parts of complex dielectric parameters (epsilon', epsilon ''), complex electrical modulus (M', M ''), and ac electrical conductivity (sigma(ac)) of Al/ZnO/p-GaAs type structure were studied as a function of frequency and voltage through the Impedance Spectroscopy Method. For this purpose, both the capacitance (C) and conductance (G/omega) of the structure was carried out at wide frequency range (1 kHz-1 MHz) and voltage range (+/- 1.2 V). It is indicated that these parameters are considerably sensitive to relatively-low and medium frequency and voltage. The change of the parameters with frequency and voltage is thought to depend on circumstances of surface states (N-ss) and ZnO interlayer at the interface/semiconductor interface, interface-dipole polarization, and series resistance. While polarization and N-ss are active at low and medium frequency in the depletion and accumulation regions, series resistance (R-s) is active at high frequencies in the layer of accumulation. It is also found that epsilon', epsilon '', loss tangent (tan delta), and R-s decrease together with rising frequency whereas M', M '' and sigma(ac) increase under the same circumstances. The results indicated that interface-dipole polarization and N-ss can emerge more easily depending on the relaxation/lifetime of the surface states at low frequencies. The peak amplitude in the M '' - V graphics increase together with rising frequency and the peak locations move to the accumulation region because of the charges in the traps and relaxation polarization.Duzce University Scientific Research ProjectsDuzce University [2017.07.02.567, 2013.07.02.204]This study was financially supported by Duzce University Scientific Research Projects (Project Numbers: 2017.07.02.567 and 2013.07.02.204)

Total Antioxidant Capacity in Patients with Chronic Viral Hepatitis

Total antioxidant capacity (TAOC) was investigated in 38 chronic hepatitis patients (25 hepatitis B, 13 hepatitis C). Control group included 22 healthy persons. Results of the colorimetric measurements of TAOC with Randox kit showed that TAOC was significantly lower in patients with chronic hepatitis compared to the controls (p= 0.0013). The findings of this study and those of some related studies, which are limited in number, suggest that antioxidant treatment may contribute to current treatments